LOCATION FARDRAW                 CO

Established Series
Rev. JPP/DAD/JCK
10/2014

FARDRAW SERIES

The Fardraw series consists of very deep, well drained soils that formed in alluvium or colluvium from mixed sources. Fardraw soils are on fan remnants and relict stream terraces. Slopes range from 0 to 25 percent. Mean annual precipitation is about 559 mm, and mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Typic Argiustolls

TYPICAL PEDON: Fardraw loam, on a 5 percent slope in native range at an elevation of 2,600 meters. When described on May 5, 1990 the soil was moist from 0 to 127 cm (colors are for dry soil unless otherwise noted).

A1--0 to 20 cm; very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; moderate fine granular structure; soft, friable, slightly sticky and slightly plastic; moderate fine and very fine roots; 5 percent gravel, 1 percent cobbles, and 1 percent stones; neutral (pH 6.8); clear smooth boundary. (15 to 30 cm thick)

A2--20 to 28; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; moderate fine roots; 10 percent gravel and 1 percent cobbles; neutral (pH 6.8); clear wavy boundary. (0 to 24 cm thick)

Bt1--28 to 38 cm; brown (7.5YR 4/4) very gravelly clay loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few faint clay films on ped faces; 35 percent gravel, 3 percent cobbles, and 1 percent stones; neutral (pH 6.8); clear wavy boundary. (8 to 30 cm thick)

Bt2--38 to 74 cm; light brown (7.5YR 6/4) extremely stony sandy clay; brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many distinct clay films on ped faces; 25 percent gravel, 20 percent cobbles, 15 percent stones, and 1 percent boulders; slightly acid (pH 6.4); gradual wavy boundary. (38 to 76 cm thick)

Bt3--74 to 130 cm; light brown (7.5YR 6/4) very stony sandy clay, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; very hard, friable, very sticky and very plastic; many distinct clay films on ped faces; 25 percent gravel, 15 percent cobbles, 15 percent stones, and 1 percent boulders; slightly acid (pH 6.4); gradual wavy boundary. (0 to 61 cm thick)

C--130 to 152 cm; reddish yellow (7.5YR 6/6) extremely stony sandy clay, brown (7.5YR 4/4) sandy clay; massive, very hard, friable, very sticky and very plastic; 25 percent gravel, 20 percent cobbles, 15 percent stones, and 1 percent boulders; slightly acid (pH 6.4).

TYPE LOCATION: Dolores County, Colorado; about 48 kilometers north of Dolores, Colorado, along Benchmark Tower road, located about 305 meters north and 122 meters west of the southeast corner of Sec. 10, T. 40 N., R. 16 W.; Narraguinnep Mountain USGS quad.; lat. 37 degrees, 44 minutes, 14 seconds N. and long. 108 degrees, 35 minutes, 42 seconds W. NAD 27

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mean summer soil temperature - 16 to 18 degrees C
Mollic epipedon thickness - 25 to 40 cm
Particle-size control section - 30 to 60 percent sand; 5 to 30 percent silt; 35 to 50 percent clay

Rock fragments are typically rounded and of granitic or volcanic origin.

A horizons
Hue: 7.5YR or 10YR
Value: 3, 4, or 5 dry; 1, 2, or 3 moist
Chroma: 1, 2, or 3
Rock fragments: 0 to 60 percent
Reaction: pH 6.1 to 7.3

Bt horizons
Hue: 7.5YR or 10YR
Value: 4, 5, or 6 dry; 3, 4, or 5 moist
Chroma: 3, 4, or 5
Texture: clay loam, sandy clay, or clay
Clay content: 35 to 50 percent
Rock fragments: 35 to 70 percent
Reaction: pH 6.1 to 7.3

C horizon (where present)
Hue: 2.5Y to 7.5YR
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 3, 4, 5, or 6
Texture: sandy clay loam, clay loam, sandy clay or clay
Clay content: 25 to 50 percent
Rock fragments: 35 to 70 percent
Reaction: pH 6.1 to 7.3

COMPETING SERIES:
Alamaditas (CO) - have a paralithic and lithic contact at a depth of 50 to 100 cm; have a horizon of secondary calcium carbonate accumulation
Kolob (UT) - have a lithic contact at a depth of 100 to 150 cm; are slightly to moderately alkaline
Showalter (UT) - have horizons of secondary calcium carbonate accumulation
Sirref (UT) - have horizons of secondary calcium carbonate accumulation
Tatiyee (AZ) - do not have more than 45 percent sand in the subsoil

GEOGRAPHIC SETTING:
Landform: fan remnants and relict stream terraces
Elevation: 2,200 to 2,700 meters
Slopes: 0 to 25 percent
Parent material: alluvium or colluvium
Mean annual precipitation: 457 to 635 mm
Mean annual air temperature: 4.4 to 7.2 degrees C
Frost-free period: 80 to 100 days

July and August receive slightly more precipitation than other months and, although the soil remains moist from melting snow, May and June receive the least amount of precipitation.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bradfield, Narraguinnep, and Dolores series.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow and slow permeability.

USE AND VEGETATION:
Fardraw soils are used for livestock grazing and wildlife habitat. Native vegetation is mainly Gambel's oak, snowberry, Arizona fescue, muttongrass, ring muhly, and sandberg bluegrass.

DISTRIBUTION AND EXTENT: Fardraw soils are of small extent in southwestern Colorado. MLRA 36.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Montezuma County, Colorado, 1997.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 38 cm (A1, A2, and Bt1 horizons)
Argillic horizon - from 28 to 130 cm (Bt1, Bt2, and Bt3 horizons)
Particle-size control section - from 28 to 78 cm (Bt1, Bt2, and part of Bt3 horizons)

Fardraw soils have a frigid temperature regime and an ustic moisture regime.

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National Cooperative Soil Survey
U.S.A.